Safety razor blade sharpener



Se t. 14, 1937. BVSTREZOFF SAFETY RAZOR BLADE SHARPENER Filed April 20, 1936 Patented Sept- 14, 19 7 SAFETY RAZOR BLADE SHARPENER Bogoia Strezoif, Minneapolis, Application April 20, 1936, Serial No. 75,270

3 Claims.

My invention relates to sharpening devices and particularly to safety razor blade Sharpeners.

Most safety razor blade sharpeners available at the present time are so constructed that the movement of the sharpening element relative to the blade is in the direction in which the sharp edge of "the blade is directed, that is, away from said edge and normal to the length of said edge.

An object of my'invention is to provide safety razor blade sharpening apparatus wherein the movement of the sharpening element relative tothe blade is toward the sharp edge of the blade.

Another object is to provide such apparatus wherein the movement of the sharpening element relative to the blade has a component of movement in a direction longitudinally of the sharp edge of the blade.

Still another object is to provide such apparatus comprising blade holding and movement controlling structure adapted for use in cooperation with an ordinary hone or sharpening stone and operable by moving the structure in alternating directions longitudinally of such stone. 1 Yet another object is to provide such apparatus including means forturning a blade over to reverse the direction in which the sharp edge thereof is directed each time the direction of movement of the apparatus is'reversed.

A further object is to provide such apparatus of simple, rugged, light, compact and inexpensive construction and which is adapted for convenient and rapid operation. 7

These and other objects and advantages of the invention will be more fully set forth in the following description made in connection with the accompanying drawing, in which like reference characters refer to similar parts throughout the several views, and in which:-

'Fig. 1 is a top view of my safety razor blade sharpening device in operative relation with a blade and a sharpening-stone and shownin two positions relative to the stone respectively in full and dotted lines; V

Fig. 2 is a vertical section taken along the line 2 f Fig. 1 as indicated by the arrows, and 3 is a vertical'sectional view taken along the line 33 of Fig. 1 as indicated by the arrows.

Referring to the drawing. suitable handle and frame means are provided and may be in'the form of a generally U-shaped yoke 4 having a handle 5 mounted thereon as shown.

To provide an elongated element revoluble relative to frame means, an externally screw-threaded shaft 6 is journaled at its respective ends'in suitable bearings 4a formed on the free ends of the U-shaped yoke 4. The bearings may consist of inwardly facing cup-like elements as shown.

Means is provided to support the shaft 6 above a hone or sharpening stone S with which my device is used in somewhat spaced parallel relation to a sharpenin'g'face thereof, as shown, and to guide the device in forward and backward movement thereof longitudinally of the stone Si To this-end,fa pair of wheels 1, preferably provided with flanges la at the respectiveouter'sides thereof are mounted on therespective' n'dportions of the screw-shaft 6 just inwardly of the bearings 40. of the yoke '4. The wheels I are fixed to the shaft 6 relative to rotation with respect-"thereto whereby rotation of the wheels! will rotate the shaft 6. t

When the handle 5 is manipulated to my device'back and forth longitudinally of the stone S, the wheels I will roll along the respectivelongitudina'lmarginal portions of the stone S and, of course, rotate the screw shaft 6 first in one direction' and then the other in accordance-with the alternations in the direction of movement of the device longitudinally of'the stone S. The flanges laof the'wheels will follow the longitudinal side edges of the stone S'to guide the device inits movement along the upper face of the stone S and prevent lateral displacement ofthe device relative to the stone during such movement.

Means carried by the above described structure is provided for holdinga' safety razor blade B in slightly inclined relationto the sharpening face of the stone S and automatically turning over or reversing the blade B in response to reversal of the direction of movement of the device along the ston'e S so that'the sharp edge E is always disposed or directed in the same direction as thedirection of such movement. The blade holding means includes a hollow element 8, pref- V erably of generally cylindrical form' 'and being "substantially shorter than the shaft "6 'The interior periphery of the element 8 is formed into a series of internal'screw threads adapted to fit on the screw threads of the shaft 6 and the element 8 is screw-threadedly mounted on the shaft 6 thereby.

In accordance with my invention it is desired that means be provided to create a moderate frictional drag between the shaft 6 and the element 8 so that rotation of the shaft 6 will result in the element 8 rotating therewith until the element 8 has applied thereto a restraining force suflicient to overcome the frictional drag-and hence stop rotation of the element 8,,whereafte'r continued rotation of the shaft 6 will cause screw-produced movement of the element 8 therealong. The above described frictional drag may be provided by various means but, in the illustrated embodiment of my invention, it is provided by so proportioning the respective screw threads of the shaft 6 and the element 8 that the requisite friction will exist between the respective screw threads.

Means is provided on the element 8 for holding a safety razor blade in a position extending radially of the shaft 6, that is, in a plane containing the axis of the shaft 6, with the sharp edge of the blade parallel to said axis and outermost so as to be directed away from the shaft 6. To this end a radially projecting pair of slightly spaced blade holding plates or leaves 8a are mounted at their inner edges on the as the same rotates.

apart to frictionally engage the respective sides of a safety razor blade B disposed therebetween as shown. 7

In use of my device a safety razor blade is placed between the blade holding leaves 8a as shown when the element 8 is disposed at or near its lower limit of movement on the screw shaft 6 (as viewed in Fig. 1). The device is placed on the right hand end (as viewed in Fig. 1) of a hone or sharpening stone S with one side of the sharp edge E of the blade B resting upon the stone S and the edge E pointing toward the left hand end of the stone S. The device is then pushed longitudinally of the stone S to- .ward the left hand end thereof guided by the wheel flanges 1a. Engagement of the edge E of the blade B with the stone S prevents rotation of the blade holder with, the screw shaft 6, and accordinglythe blade holder is progressed upwardly along the screw shaft (as viewed in Fig. l) to' produce a component of-motion of the blade B laterally of the'stone S as the edge E progresses longitudinally of-the stone S. When the device reaches a position approximating the position thereof shown in dotted lines in Fig. 1

the device is reversed in direction of movement and is then drawn toward the right hand end (as viewed in Fig. 1) of the stone S. As reverse movement is started the blade holder rotates with the reversely rotating screw shaft until the blade B has turned over to point toward the right hand end of the stone S, with the second side of the sharpedge E thereof in engagement with the stone S whereafter, as movement of the device toward the right is continued, the blade holder will move downwardly along the screw shaft 6 to again produce a component of motion of the blade B laterally of the stone S as the edge E is progressed longitudinally of the stone S. e

From the above it should be clear that the bladeholder and the blade B will be turned over or reversed each time the direction of movement of the device is reversed so that the effective movement of the stone S relative to the blade B is always toward rather than away from the sharp edge E of the blade B and is in a direction angularly displaced from a line normal to the edge E by an acute angle. Such relative movement closely approximates the movement a barber uses in honing a straight-edge razor and produces an edge of superior qualities.

The friction between the respective screwthreads of the screw shaft 6 and the cylindrical element 8 of the blade holder causes transmission sharpening device which is capable of improved results.

'It will, of course, be understood that various changes may be made in the form, details, proportions and arrangement of parts, without departing from the scope of my invention, which, generally stated, consists in a device capable of carrying out the objects above set forth, and in the novel parts and combinations of parts disclosed and defined in, the appended claims. -What is claimed is: 7 a I J 1 l. A device for cooperation with a sharpening stone to sharpen the sharp edge of a blade comprisin structure ,adapted to be moved longitudinally of a stone in alternate directions and including, a revoluble element adapted for disposition transversely of said stone, the end portions of said element being of enlarged diameter and adapted for rolling longitudinally of said stone on the longitudinal marginal portions thereof,-the medial portion of said element being externally screw-threaded, and a blade holding member swingably, screw-threadedly mounted on saidelement in yielding frictional engagement therewith whereby reversal of the blade is accomplished, said blade holding member being arrangedto hold a blade in a plane disposedradially of said element and with the sharp edge of said blade outermost "and parallel to, said element so that the blade will be slightly inclined relative to said stone when said sharp edge is. in engagement with said stone whereby said blade will be swung from one side to the otherof said element at each reversal of the direction of said movement so that the sharp edge of the blade will be directed in the direction of said movement, and whereby a component of movement of said blade laterally of said stone will accompany movement longitudinally of said stone.

2. A device for holding and guiding a sharp edged blade when sharpening said blade on a sharpening stone comprising, a handle, an elongated externally screw-threaded element connected to said handle for rotation of said element about its longitudinal axis relative to said handle, wheels fixedly mounted on the respective ends of said element to roll longitudinally of said stone on respective longitudinal marginal portions of a face of said stoneso as to rotate said element, and a blade holding member shorter than said element and having an internally screw-threaded portion mounted on the screwthreads of said elements in moderate frictional engagement therewith so as to tend to turn therewith, said member being arranged to hold'a blade in radial relation to said element with-its sharp edge outermost and disposed parallel to said element and to move laterally and reverse its position solely under the influence of said element.

3. A device for cooperation with a sharpening stone to sharpen the sharp edge of a blade com- ;prising, a U-shaped yoke, a handle mounted on said yoke, a shaft journaled at its respective ends in the respective free end portions of said yoke, a pair of flanged wheels fixedly mounted on said shaft immediately inwardly of said respective free end portions with the flanges thereof outermost whereby said wheels may run longitudinally of a sharpening stone on the longitudinal marginal portions of a face thereof to maintain said shaft in transverse, somewhat spaced parallel relation to said face and said flanges may engage the longitudinal edges of said stone to guide said device, external screw threads formed on said shaft in the portion shaft with the sharp edge of said bladeouter- 10 most and parallel to said axis.

BOGOIA STREZOFF. 

